/*
 * TextServices / TSDotNet / TSNative
 * Marco Maria Bellocchi, Mauro Bampo
 * Copyright(c) 2013.
 * 
 * The MIT License
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * 
 */

// MB 25/01/2013: Created

#pragma once
#include "stdafx.h"
#include "Filter.h"

namespace TSNative {
	
	namespace Filters {

		/// Encodes pairs of chars onto a single char, through a dictionary.
		class CharToNibbleDecoder : public Filter {

		private:
			const char* _pDictionary;

		protected:
			const char* Dictionary();

		public:
			/// The dictionary must be a 16-char array with each value representing the character being encoded as the 4-bit index of the value.
			/// The value at index 0 should never appear twice in a row in the input string, as that would generate a terminator in output.
			/// The value at index 15 should never appear in the input string as that is used as padding for odd-length strings.
			CharToNibbleDecoder(const char* pDictionary);
			virtual int GetInitialBufferLength(int nInputLength);
			virtual FilterState Process(const char* pInput, int inputLength, char** ppBuffer, int bufferLength, FilterState inputState);
		
		};

	}

}